Q. 165.0( 1 Vote )
Mark the correct alternative in the following:
If A and B are two disjoint sets, then n
is equal to
A. n(A) + n(B)
B. n(A) + n(B) − n
C. n(A) + n(B) + n
D. n(A) n(B)
Answer :
Here, A and B are two disjoint sets.
⇒A⋂B=ϕ
⇒n(A⋂B)=0
n(A⋃B)=n(A)+n(B)-n(A⋂B)
=n(A)+n(B)-0
=n(A)+n(B)
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